#!/usr/bin/env python
# -*- coding: utf-8 -*-


# =============================================================================
# Copyright (C) 2013-2014 Andreas Kührmann [andreas.kuehrmann@gmail.com]
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
# =============================================================================


import numpy as np

from .. import baseclass as bcls


class Chebyshev(bcls.BDObject):
    def __call__(self, sample_rate):
        chebyshev = np.cos(np.pi * np.arange(sample_rate) / (sample_rate - 1))
        return (chebyshev * .5 + .5)[::-1]
